At least two people have died and several others have suffered non-fatal heart attacks and minor injuries following the 7.5 magnitude earthquake.
Emergency services have confirmed one death at the Elms Homestead in Kaikoura. Three people live at the historic home. One person was able to escape, one was rescued and third has died. Relatives of the family are having trouble contacting emergency services due to congested phone lines and power cuts.
A second person has died of a heart attack at a property in Mt Lyford and there are reports of several people suffering non-fatal heart attacks in the hours following the main quake.
Police in Christchurch are continuing to respond to calls for help, and from people reporting damane. "
"Police are working closely with Civil Defence, who are leading the response, as well as Fire, St Johns and other emergency services to ensure the safety of the public," a spokesperson said.
"Police staff are continuing to patrol the community and are responding to business as usual, as well as responding to reports of damage and requests for assistance. (Our) main concern at present is maintain the safety and wellbeing of the public, while still responding to emergencies that may arise."
St John has activated its National Crisis Coordination Centre and has set up local Emergency Operation Centres in the South Island. A spokeswoman said St John staff, resources and emergency equipment have been relocated to higher ground, and resource is being moved to affected areas in order to maintain response capability. Casualty numbers and injury numbers are unknown at this stage.
The Ministry of Civil Defence said injuries have been reported in Canterbury and evacuations have occurred in Canterbury, Marlborough, Nelson/Tasman, Wellington, Manawatu/Wanganui and the Chatham Islands.
"The number of injuries and evacuees are not known at this time."
Ministry of Civil Defence & Emergency Management Director, Sarah Stuart-Black said, 'the New Zealand public have responded, and continue to respond, to the earthquakes and tsunami warning in a calm and safe way. We've seen evacuations in most of the at risk areas and know that many New Zealanders have been checking in with friends and loved ones since the quakes began at midnight.'
'I want to particularly thank those who evacuated, either at their own discretion or after receiving instructions to do so. Your strength, trust and willingness to do the right thing not only helps to keep people safe, but makes our jobs and the jobs of other emergency services much easier
Speaking from the Beehive's civil defence bunker, Prime Minister John Key said all 16 regions had activated civil defence requirements. Tsunami warnings replace in place for much of the East Coast where ways of up to 2m have already stuck.
Key said it was important for people to keep following safety advice.
He said New Zealand was in "great shape" to meet any costs from the quakes, but expected there would be significant repairs needed. He also confirm the two deaths.
Acting Civil Defence Minister Gerry Brownlee said the pressing need was to get communications gear in to cut off areas and that would be the first task for the helicopters.
He said there weren't reports of many homes or other buildings brought down.
While there had been reports of items falling from shelves, some cracks in buildings and smashed windows in Wellington the true extent of property damage is being revealed as emergency service workers begin assess infrastructure and homes in the light of day.
As information continues to flow in Civil Defence are receiving multiple reports of damage to property in the South and North Islands. Damage has been reported in the Canterbury, Blenheim and Wellington regions, including widespread damage and building collapses reported in Kaikoura.
Pictures are also coming in of large slips and badly damaged roads in the Hurunui District. The small North Canterbury town Waiau, where a bridge has been badly damaged, is shut off.
Kaikoura has also been cut off but reports of bad damage are hard to substantiate due to power cuts, blocked roads and a congested mobile network. Military helicopters would be going there to assess damage and make contact. The Fire Service is also sending a seven-strong Urban Search And Rescue squad from Christchurch by helicopter.
Assessment teams are also being sent to Waiau and Blenheim.
In Wellington the TSB Arena and BNZ Centre have sustained the most damage. There is damage to wharves and the Inter Islander terminal, and the Tory Channel remained closed.
Shipping workers were forced to flee the Kings Wharf freight shipping terminal in Wellington, after cracks began appearing and water spurting from beneath them.
"It was just panic stations," said the man who did not wish to be named.
"Water was coming up from the wharf, we had about five seconds to evacuate."
The man said he and seven of his colleagues all ran out together, and huddled to protect themselves in case glass or debris fell from nearby buildings.
In Marlborough, emergency services are bracing themselves for an influx of calls as people see the extend of the damage.
Rural fire chief Richard McNamara said there was a number of vehicles stuck on State Highway 1, and a helicopter was waiting to survey the road in daylight.
"There will be a few people spending the night in their cars, I would say."
He urged people not to travel unless it was urgent, because there was already congestion.
"There has been significant tidal movement in Picton and the [Marlborough] Sounds."
McNamara said welfare centres in Rarangi and Waikawa were sheltering about 100 people, including residents of a rest home.
Buildings have reportedly fallen in Bleheim.
"Fire crews are roving the towns and CBD of Blenheim since the earthquake assisting where they need to and will continue that throughout he day."
Psychologist Nigel Latta has posted advice on social media for coping with the mental impact of the quake, particularly for children.
"Reassure your little people. Keep calm and carry on best message for kids," he posted on Twitter.
"Tell your kids aftershocks are just the earth farting. Have a laugh where you can. Follow news but try and get kids focus off news."